There's a scene in Season 7, Episode 5 of the eternal animated sitcom "The Simpsons" in which perpetual 8-year-old Lisa Simpson announces to her family that she will no longer eat meat of any kind.

“Lisa’s Substitute,” a season-two episode of The Simpsons written by one of the most reliably great storytellers in the show’s history, Jon Vitti, may not have been the first Simpsons episode to make ...